Rough Idle, No acceleration

[ianboo]

Hello everyone. I recently just bought another supra mk3 1989 turboed 5 speed manual. I changed the fuel pump and spark plugs and put new gas in the tank. When I start the car up it catches and idles really rough. The motor is shaking and is around 400~500 rpm. Sounds like its only running on a couple cylinders. I am getting no diagnostic codes, the light just keeps flashing. Also the car does not accelerate. If I press the gas while it is idling, nothing happens, just sounds like its choking itself out more. What could this be?

The car sat for 2 years, I changed the oil and radiator fluid also.

Also wiring is all jimmy rigged, maybe that's why it is not throwing codes?

 

[ianboo]

I'm guessing a coil pack is bad, will test tomorrow and let you guys know

 

[supraguy@aol]

It's hard to tell, since your wiring is compromised.

My question is- Why did the car sit for 2 years? Was there a repair that it needed? I bought my '89 a couple months ago, and it had sat for 7+ years.
I did all the same pre-start repairs as you, plus the fuel filter. If any disassembly was done, check the CPS position at top dead center. I could see a retarded cps causing
low idle, no acceleration, etc.
Also, as you mention, check the coilpacks as per tsrm. It should be easy to tell if one or more of your cylinders is not firing.

 

[cinderMK3]

when I first got my supra had my brother helping me just put things together,
He forgot to push the Inter-cooler tube from the turbo's outlet to the inter-cooler, it sounded just like that and could not be throttled until it was fixed.
add this to the list, Check hoses and IC tubeing

 

[ianboo]

Okay so I seafoamed the car and now its idling fine and accelerating. But during acceleration it stops rhymetically for a short time. Im getting engine code 31 which is the AFM. It's a Lexus AFM. Does the connector not always fit in all the way with the stock harness?

 

[ianboo]

How do you know if the AFM is getting power?

 

[supraguy@aol]

The code 31 indicates that there is an issue with the afm sensor, so the Lexus housing shouldn't cause this.
The sensor is identical in both cars, so the afm plug should fit the sensor, no issues. It is common for these afm's to get fouled up over time. There is no good way to clean
the internals, as any spray cleaner with destroy the sensor's ability to measure correctly. Verify that the sensor is plugged in, and you can test the afm/wiring per tsrm.

 

[supraguy@aol]

PS- Do you have 550cc injectors to match the Lexus housing?
Otherwise, you're probably getting AFR issues as well.

 

[Nick M]

[video=youtube;2sh0wr7HH8Y]https://www.youtube.com/watch?v=2sh0wr7HH8Y[/video]